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Makita GA4030K Troubleshooting

A Makita angle grinder released in June of 2010. Model number GA4030K.

The is device not powering on when switch is engaged ¶ 

The cord is not plugged in all the way or the device is not receiving power ¶ 

If the grinder is not turning on, the most common issue is that it is not receiving power. To fix this, make sure the tool is powered off and completely remove the plug from the wall outlet then reconnect it. If the device still won't power on, plug something else into the socket to make sure the fuse or the outlet has not blown.

Frayed or disconnected power cable ¶ 

A frayed power cable requires disassembly of the device body and then replacement, while an internally disconnected power cable requires disassembly of the tool body and then reconnection of a few screws to reattach the cable to the power sink. See the electrical cord replacement guide for further instructions.

Broken or disconnected switch ¶ 

This is similar to a frayed or internally disconnected power cable. A broken or internally disconnected power switch requires disassembly of the device's body for replacement and reconnection. See the switch replacement guide for further instructions.

Sparks or Smoke when the device is being operated ¶ 

Worn or broken carbon brushes ¶ 

The most likely cause of sparks and/or smoke is disconnection or wearing down of the carbon brushes. The carbon brushes are two pieces of an electric motor which transmit current to the rotating armature via the commutator. When worn or broken carbon brushes interact with the communicator abnormally, they can produces sparks and/or smoke. See the carbon brush replacement guide for further instructions.

Broken armature ¶ 

Often sparks and/or smoke can be caused by a broken armature. The communicator (which is part of the armature) may have been damaged or broken by the carbon brushes. Overworking the tool may also cause the armature to break by burning out the windings (the copper wires in the armature). In either case, see the armature removal guide and check for any visible damage.

Unnecessary or unusual noise during operation ¶ 

Overworking the machine (lack of cool down time) ¶ 

Apply less pressure to the angle grinder when grinding a surface or after working a hefty job. It is recommended to let the grinder spin freely for a couple of seconds to allow the tool to cool down. Give the angle grinder some time to cool down after any job and refrain from continued use over long periods of time.

Slow performance ¶ 

Wrong kind or unbalanced disk ¶ 

Because an angle grinder is a multipurpose tool, it comes with multiple wheels and disks. Make sure the correct size and type of disk is being used for the task at hand. After checking the disk, look for signs of the disk deterioration such as dull blades, chipped edges, cracks, or uneven wear.

Worn carbon brushes ¶ 

If the angle grinder is not spinning at a constant speed or is slower than normal, the carbon brushes may be worn down. The carbon brushes are two pieces of an electric motor that transmit current to the rotating armature via the commutator. Worn carbon brushes can decrease the overall performance of the motor. See the carbon brush replacement guide for further instructions.

Power loss over a large amount of extension cable ¶ 

Turn device off completely before unplugging it from the extension cord. Try plugging the device directly into a wall outlet to see if the performance and speed increase.

Heat coming from the body of the device ¶ 

Needs more grease ¶ 

An excessive amount of heat may be caused by a lack of grease in the wheel bearing. Grease is a lubricant which helps to decrease the amount of internal friction within the device. See the grease replacement guide for further instructions.

Needs to be cleaned ¶ 

There may be dirt, sand, or metal bits in the grease that would create friction thus causing heat. This can be fixed by cleaning the inside of the device. See guides for replacing the armature and replacing the grease and then blow with compressed air.

One Comment

I have a makita angle grinder that won't work on my generator but does work on the mains. I've used several other higher wattage power tools on the genny and all work fine so cant see why the angle grinder wont . Any clues???

Alan Read - Reply

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